For decades, liberal journalists have often tried to discredit conservative protest movements, from the tea party to the pro-lifers, by smearing them with violent extremists. So it's fascinating to read liberal Washington Post media columnist Margaret Sullivan warn on Sept. 4 against tarring the anti-Trump "resistance" with an antifa brush. The headline read "Quick to Vilify, But Slow to Explain It."

Sullivan claimed that all most people know about antifa, the far-left-leaning militant groups, is what they've heard from President Trump and what they've guessed from video of "club-wielding protesters shown endlessly on TV." This leads them to think antifa members are "the left-wing equivalent of neo-Nazis." Sullivan said, "That's not only untrue, but it has the effect of tarring everyone who protests Trump, as well as those who peacefully march for climate-change awareness or rally against hate-mongering speakers."

She complained that the term "antifa" has been "quickly weaponized" and quoted leftist writer Paul Blest to claim that antifa's level of violence is nearly nonexistent next to the extremist right. Blest said, "To pretend that the alt-right and Antifa are comparable is like equating the danger of playing Russian roulette with taking a walk."

Try asking someone beaten half to death by antifa thugs whether it felt like a walk in the park.

In Sullivan's mind, the so-called alt-right has faced an easy road. She bizarrely claimed that "a prettied-up celebrity status accrued to white-nationalist leader Richard Spencer, who was profiled everywhere with flattering photos and reasonable-sounding quotes." But she didn't provide a single example of a media outlet, liberal or conservative, flattering Spencer with "prettied-up celebrity status" ... because it didn't happen.

ABC's interviews of Spencer were described on-screen with words like "Hate Among Us" and "Confronting Hate." He openly talked about an approaching race war, which is not very "reasonable-sounding." Sullivan's own Washington Post described him with headlines like "Richard Spencer's Vision: Apartheid in America" and "Six Angry Men and Their Long Roads of Hate."

Sullivan also relayed questionable numbers from the Anti-Defamation League, or ADL. She said: "Right-wing extremists committed 74 percent of the 372 politically motivated murders recorded in the United States between 2007 and 2016. Leftwing extremists committed less than 2 percent."

Of course, most conservatives don't consider the Hitler-adoring National Socialist extremists to be right-wing. Worse yet, Sullivan was wrong to claim that the ADL only counted "politically motivated" murders. Its "Murder and Extremism in the United States in 2016" report explicitly stated that it counted all murders by the extremists it identified, including "non-ideological" murders in the midst of "gang-related and traditional criminal activity."

Sullivan also stated, "Mainstream news organizations and liberal politicians are quick to criticize antifa -- doing so vehemently has become a badge of honor -- but less quick to explain the group's ideology, tactics or goals." To her chagrin, Democrats like House Minority Leader Nancy Pelosi and the Washington Post editorial board are coming around to the idea of properly vilifying antifa as a violent fringe.

Sullivan lamented that antifa theorist Mark Bray, a professor at Dartmouth College, was "publicly slapped back by his university president." She lectured reporters: "The best thing journalists can do is to relentlessly explain the beliefs, scope and scale of antifa, and to resist conflating it with liberal groups." NBC's Chuck Todd has already put Bray on air twice to promote antifa's explicit endorsement of violence. And NPR's talk show "1A" gave Bray an hourlong platform to explain it.

Sullivan and Todd look especially odd because the liberal media have protested so harshly against President Trump denouncing journalists for fake news. Antifa thugs have repeatedly beaten or threatened journalists and regular citizens on the street who dare to capture them on tape. Why, then, must they not be "vilified"?